1. Field of the Invention
This invention relates to a digital exposure type photo processing apparatus having an illuminating optical system for radiating films with illuminating light, a photoelectric converter for reading light transmitted through the films and converting the light into image data, and an image processing device for processing the image data to generate print data.
2. Description of the Related Art
The digital exposure type photo processing apparatus is attracting attention in the photographic printing industry today. This type of photo processing apparatus converts frame images of a photographic film into digital image data by means of a film image reading device, instead of exposing the frame images to light. This digital image data is put to a color density adjustment, size changes, image synthesis and so on based on a predetermined algorithm, to produce print data. This print data is used to expose photographic paper with a digital printer, thereby visualizing the frame images on the photographic paper to obtain photographic prints. The digital printer may be any of various types including the optical modulation laser beam exposure type, liquid crystal shutter type, CRT exposure type, and fluorescent beam exposure type. In any case, such a digital printer forms latent dot images by exposing photographic paper after adjusting the irradiating intensity of each of RGB colors according to a density level of each color of the pixels constituting the digital image data. The exposed photographic paper becomes hard copies of original images, i.e. photographic prints, after a developing process.
The digital exposure type photo processing apparatus described above may be regarded as having a construction in which the projection exposure unit of a conventional projection exposure type photo processing apparatus is replaced by a film image reading device and a digital printer. That is, in the projection exposure type, photographic paper is exposed directly by light emitted from the illuminating optical system and transmitted through a film. In the digital exposure type, light transmitted through a film is once converted into image data by a photoelectric converter, and print data generated from the image data is used to drive the digital printer to expose photographic paper. However, the digital exposure type and projection exposure type, although different in using directly or indirectly the light transmitted through the film, are not very different in the basic technical concept of acquiring visible photographic prints by printing film images on photographic paper.
Photographic prints are of poor quality when, for example, the prints include peripheries of image frames acting as image pickup regions. Trimming such unwanted parts from the prints afterward is a very troublesome operation. Thus, a film mask with an aperture size slightly smaller than the size of the image frames is normally used so that light from peripheries of the image frames may be excluded from the transmitted light. Such a film mask, while providing an advantage that photographic prints include no blanks printed thereon, fails to allow images formed to the very edges of the image frames to be printed completely. The customer is likely to make a complaint when an omitted part of the image is a part of the main photographic object.
Having regard to the state of the art noted above, an object of this invention is to provide a digital exposure type photo processing apparatus for simply and reliably printing only photographed film images on photographic paper.
The above object is fulfilled, according to this invention, by a digital exposure type photo processing apparatus comprising an illuminating optical system for emitting light to a film; a photoelectric converter for reading light transmitted through the film and converting the light into image data, the transmitted light being read in a size larger than each image frame of the film; and an image processing device for processing the image data, the image processing device including an actual image extractor for dividing the image data into actual image data corresponding to the image frame, and peripheral image data corresponding to regions around the image frame, print data being generated from the actual image data for application to a digital printer.
With this construction, the image data acquired by the photoelectric converter includes data of the peripheries of the image frame as well. Thus, each photographic image is acquired in full. Next, the image data is divided, based on density level and density distribution characteristics, into actual image data representing the frame image corresponding to an exposed region of the film, and peripheral image data representing regions around the image frame corresponding to unexposed regions of the film. Print data is produced from the actual image data. Consequently, the print data made includes the entire photographic image corresponding to the exposed region of the film, and excludes the peripheral image corresponding to the unwanted, unexposed regions. A photographic print made by a digital printer shows only a visualized photographic image itself.
Where, for example, fireworks in the night sky are photographed, there occurs little difference in density level and density distribution between actual image data and peripheral image data. It is difficult to distinguish therebetween automatically. To solve such a problem, the digital exposure type photo processing apparatus in one preferred embodiment of this invention further comprises a video processor for displaying the actual image data and the peripheral image data on a monitor, a manually operable input device, and a boundary corrector operable in response to an instruction received from the input device for correcting a boundary between the actual image data and the peripheral image data. That is, the actual image data and peripheral image data are displayed on the monitor, and the operator, while looking at its display screen, can determine a boundary between the actual image data and the peripheral image data. By successively displaying all frame images, the operator may check all the images even before exposing photographic paper, thereby to improve the quality of photographic prints. To facilitate the operation by the operator to determine a boundary between the actual image data and the peripheral image data, it will be of advantage to display a frame on the monitor which the operator may move up and down and right and left. For the same purpose, the peripheral image data may be displayed in a single color, such as black or gray, to facilitate its distinction from the actual image data.
Further, in a preferred embodiment of this invention, apertures of a film mask for determining regions of the film illuminated by the light are set to be larger than a width of standard image frames, and to be inwardly of film perforations, with respect to a direction of width of the film. With this construction, light of an area larger than each image frame but not extending to the film perforations enters the reading portion of the photoelectric converter usually formed of CCDs. The illuminating light of high intensity having passed through the perforations and entering the photoelectric converter as it is would adversely affect a photoelectric conversion of other regions. The above film mask is effective to avoid such an inconvenience, and also avoid a deficiency of image data of the photographed, exposed regions of the film. Where the film to be read is the APS type having film perforations arranged along only one side thereof, the apertures are set to be larger than the width of standard image frames, and to be inwardly of the film perforations and the opposite edge of the film, with respect to the direction of width of the film.
Other features and advantages of this invention will be apparent from the following description of the embodiments to be taken with reference to the drawings.